<?php
header("Content-type:text/html; charset=utf-8");
require_once 'db_conn.php';
$conn;

$sql = "SELECT * FROM t_message";
$result = $conn->query($sql);
//print_r($result)  ;

//echo $result->field_count;

echo "<pre>";
//print_r($result->fetch_array());
//print_r($result->fetch_assoc());
$rows = $result->fetch_all(MYSQLI_ASSOC);
print_r($rows);
foreach ($rows as $value){
    echo"<br/>";
    echo $value['username']."说: ".$value['content'];
}